| Investigation | Explanation |
|---|---|
| Loop recorders (reveal monitor) | This is a small battery powered device which is implanted under the skin and records the heart rate and rhythm to identify if there are any problems. It is suited to patients who have described infrequent symptoms and can remain in place once the abnormal rhythm has been isolated. It is then removed after a period of time. |
| Myocardial perfusion scintigraphy: | Also known as a thallium scan, this shows how well the blood reaches the cardiac muscle through the coronary circulation. A small amount of thallium is injected into a vein and is then visualised by a moving camera outside of the body. Thallium does not travel well to areas of poor blood supply, therefore, the pictures demonstrate the amount of blood reaching cardiac muscle. |
| Coronary angiography (also called cardiac catheterisation): | This is a specialised x-ray of the heart which can be used to assess damage to the heart and for cardiac assessment. A catheter tube is inserted under local anesthetic into the main artery in the upper leg or lower arm and passed into the aorta. Dye is then injected which illuminates the coronary circulation. (This will be discussed in more detail in Modules 3 and 4), |
| Magnetic Resonance Imaging (MRI) : | This scan uses a magnetic field to produce detailed images of the heart and blood vessels. It is very helpful in gaining images from patients whose vessels and anatomy are difficult to see using angiography. |
| Electrophysiological studies: (EP studies) : | This allows the heart’s electrical activity to be analysed in great detail. This test has revolutionised the way we understand and treat fast or abnormal heart rhythms. Catheters are placed into a vein (usually in the groin). Then it is gently moved into position within the heart. There, the special electrode tip stimulates the heart and records the subsequent electrical activity. |
| Trans-oesphageal echocardiogram (TOE/TEE): | This is a specialised echo scan which involves passing a tube into the oesophagus and can examine the heart to give a different view from the back (posterior) of the heart rather than the front. It is used when cardiologists require specific information often in relation to the valves or any infective components. |
| CT scans of the heart: | Computerised tomography (CT) has been around since the 1970s. There are two ways in which a CT scan can be used to examine the heart – one is a CT coronary angiogram and the other is a CT calcium score.
A CT scan produces multiple images of the heart from different angles, which the cardiologist can then see on a computer screen. The images are picked up using detectors. The greater the number of detectors (the UK’s most commonly used version has 64) the clearer the image and the more useful it is in helping the cardiologist to make a diagnosis. |
| CT coronary angiogram: | A CT coronary angiogram is used to measure the blood flow through the coronary arteries. Similar to a conventional coronary angiogram, a CT coronary angiogram involves injecting an iodine-based dye into the bloodstream to highlight the blood vessels. However, unlike the traditional angiogram, which is a sophisticated x-ray of the arteries, the dye is injected into a small vein in the arm rather than an artery in the groin. The CT coronary angiogram is useful if the cardiologist thinks that it is unlikely that the patient has coronary heart disease but he or she cannot explain what is causing the patient’s symptoms. it is often used to rule out coronary heart disease, rather than to confirm it. It can also be useful if the patient has developed heart failure but the underlying cause of this is not clear. If coronary heart disease (CHD) is suspected, a traditional coronary angiogram is done. Another reason for this investigation is a suspicion that there may be an abnormality in the structure of the heart. |
| Stress Echo: | Occasionally, an echocardiogram is done while the heart is “under stress”. This is done by increasing the heart rate with either exercise or medication. This test can help to diagnose coronary heart disease, heart failure and cardiomyopathy. |
Reference: British Heart Foundation
Pulse point
There are other cardiac investigations not explored above. It is useful to access to patient information booklets which can provide information on these to staff and to patients/carers. Some of these further investigations will be discussed in the other modules and cases within the HEARTe resource.
Page last reviewed: 22 May 2020
